Israel's parliament has given initial approval to a bill that would make it a crime to publicly deny Israel's right to exist as a Jewish state, punishable by a sentence of up to a year in prison.
It is the latest of several new measures that critics have denounced as an assault on free speech, particularly for Israeli Arab citizens.
Most Israeli Arabs, who make up about a fifth of Israel's population, are descended from Palestinians who remained in the country after hundreds of thousands either fled or were driven away in fighting over Israel's founding in 1948.
The measure has to pass three additional votes in parliament and a committee review before becoming law.
US President Barack Obama has drawn a line on Israeli settlement expansion, before he meets on Thursday with Palestinian president Mahmoud Abbas as part of his urgent quest to revive peace talks.
Secretary of State Hillary Clinton says Mr Obama made it clear, when Israeli Prime Minister Benjamin Netanyahu visited the United States last week, that he wants "no natural growth exceptions" to his call for a settlement freeze.